1. Field of the Invention
The present invention relates to die stamping and, more particularly, to a stamping die used in a punch press.
2. Discussion of the Related Art
Various methods are used in conventional production of metal parts. One such method is stamping, in which stock material, typically a metal sheet, is fed into a punch press and a metal part, such as a hole, a notch, an L-shaped holder is formed. The stamping die parties a critical component of the punch press system.
Referring to FIG. 8, a typical stamping die 10 includes a base set 11 and a stripper plate 12. The base set 11 has a punch 111 formed on the center of the base set 11, and the punch 111 is integrally formed with the base set 11. The stripper plate 12 is disposed on the base set 11. A through hole 121 is defined in the center of the stripper plate 12 corresponding to the punch 111, and the punch 111 is configured to pass through the through hole 121. A plurality of helical springs 112 are disposed between the base set 11 and the stripper plate 12, acting as buffer. When the base set 11 is moved upwards by external force, the helical springs 112 compress and impel the stripper plate 12 to contact a workpiece firmly, such that the punch 111 passes through the stripper plate 12 and punches a hole in the workpiece.
Because the punch 111 is integrally formed with the base set 10, punching is restricted to a single shape. When a new product requires a hole of different shape, a new stamping die 10 must be pre-fabricated correspondingly. The conventional stamping die 10 thus presents disadvantages, such as long production cycle and high production cost. In addition, over time, the punch 111 is subject to wear, requiring replacement of the entire stamping die 10.
What is needed, therefore, is a stamping die that overcomes the described limitations.